Mesoporous transition metal oxides with crystalline walls show promising applications in catalysis and energy storage. Syntheses of those crystalline mesoporous oxides, however, currently remain as an unmet challenge because of the large volume shrinkage during crystallization in a sol-gel process. Here, we demonstrate a facile and general template-free method to prepare six mesoporous transition metal oxides, e.g., CuO, CoO, and spinel MCo₂O₄ (M = Co, Cu, Mn, Zn), with highly crystalline walls and continuous mesopores in the forms of two-dimensional nanoplates or nanosheets. The method is based on the thermal crystalline transformation from basic carbonates to mesoporous metal oxides. The crystal interconversion not only endows the crystallinity and mesoporosity of oxides but also generates abundant surface-step defects that show remarkable enhancement of the catalytic activity of porous oxides. Our method likely provides an alternative paradigm for cost-effective and universal synthesis of crystalline mesoporous oxides beyond the traditional templating methods.

具有晶体壁的中孔过渡金属氧化物在催化和能量存储中显示出有希望的应用。然而，由于在溶胶-凝胶法中结晶期间的大体积收缩，这些结晶中孔氧化物的合成目前仍是未解决的挑战。在这里，我们演示了一种简便且通用的无模板方法来制备六种介孔过渡金属氧化物，例如CuO，CoO和尖晶石MCo ₂ O ₄（M = Co，Cu，Mn，Zn），具有高度结晶的壁和呈二维纳米板或纳米片形式的连续中孔。该方法基于从碱性碳酸盐到中孔金属氧化物的热结晶转变。晶体互变不仅赋予氧化物以结晶度和中孔性，而且产生大量的表面台阶缺陷，这些缺陷显示出多孔氧化物催化活性的显着提高。我们的方法可能为传统的模板方法提供了一种成本有效且通用的结晶中孔氧化物合成方法。